
varying float vSize;
uniform vec3 uColor;

void main(){
  float distanceToCenter = distance(gl_PointCoord, vec2(0.5,0.5));
  float strength = 1.0 - distanceToCenter * 2.0;

  if(vSize<=0.0) {
    gl_FragColor = vec4(0, 0, 0, 0);
  } else {
    gl_FragColor = vec4(uColor, strength);
  }
}